The measured voltage maps subject to the primary and two different secondary currents. The voltage distribution on the three imaging planes corresponding to the selection of the current driving electrodes for (a) the primary injection, , two secondary injections, (b)
, and (c)
when filling it with homogenous agar. (d)–(f) are the voltage difference maps of u-u
0 when applying primary and two secondary currents with the three objects.